save_gdal.py: support UTM projection

[pbrotoisworo]

Description of proposed changes

• Add EPSG to file attributes in readfile.py
• array2raster now accepts additional argument for EPSG code in save_gdal.py (default is 4326). This loads the EPSG from file attributes.
• Fix typo in array2raster function

Reminders

• Fix save_gdal.py does not work with hyp3 data #644
• Pass Codacy code review (green)
• Pass Circle CI / local test (green)
• Make sure that your code follows our style. Use the other functions/files as a basis.
• If modifying functionality, describe changes to function behavior and arguments in a comment below the function declaration.
• If adding new functionality, add a detailed description to the documentation and/or an example.

[yunjunz]

Thank you @pbrotoisworo!

[yunjunz]

Installation failed on Circle CI but testings on my local machine passed without issues. The circle CI issue is not related to the code change in this PR (scikit-image/scikit-image#5528), so it's fine to merge.